Find All Numbers Disappeared in an Array
一个n大小的数组, 返回里面缺的元素. 这个就是map一下.
public class Solution {
public List<Integer> findDisappearedNumbers(int[] nums) {
List<Integer> res = new ArrayList<>();
int n = nums.length;
for (int i = 0; i < nums.length; i ++)
nums[(nums[i]-1) % n] += n;
for (int i = 0; i < nums.length; i ++)
if (nums[i] <= n)
res.add(i+1);
return res;
}
}